The previously UNESCO initiated policy of inclusive education has been adopted by the Indonesian government since 2003. As a new policy, inclusion will require many changes in the existing system of education which tends to be segregative. This research investigated the effects of a two-day workshop on parents attitudes, teachers' competence and knowledge related to inclusive education. The subjects of the study were 50 parents and 50 teachers of 25 primary schools from 25 subdistricts in the district of Wonogiri, Indonesia. They took part in a two-day workshop in inclusive education using active learning modes of presentation. Teachers' knowledge was measured using a written test, while parents' attitudes and teachers' competence were measured using Likert type scales. The results showed that: (1) The two-day workshop in inclusive education significantly improved parents' attitudes toward inclusive education. The mean score of parents' attitudes before workshop was 137,26 (SD = 17.383), and the mean score after workshop was 148,46 with a standard deviation of 15,439. A t-test for correlated means resulted in a p = 0.000. (2) The two-day workshop significantly improved teachers' knowledge about inclusive education. The mean score of teachers knowledge before workshop was 57.60 and the mean score after workshop was 67.36, both were below the mastery criteria of 70. A T-test for correlated means resulted a p value of 0.00, indicating a significant improvement of knowledge. (3) The two-day workshop also significantly improved teachers' feeling of competence working in inclusive classrooms. The mean score of teachers' competence before workshop was 334,82 (SD = 69,857) and the mean score after workshop was 372,56 (SD = 72,505). A t-test for correlated means resulted a p value of = 0.000.